Body Temperature Organisms. 



6i 



25 samples examined in July and August, 1904, showed 

 1,690,000 bacteria per c.c. at 20 degrees and 1,400,000 at 

 37 degrees, while 429,000 per c.c. were acid formers 

 (Winslow, 1905). 



In impoUuted waters not only the absolute number, of 

 organisms developing at the body temperature, but the 

 ratio to the gelatin count, is very different. Rideal (Rideal, 

 1902) states that the proportion between the two counts 

 in the case of a London water in a year's examination 

 was on the average one to twelve. Mathews (Mathews, 

 1893) in 1893, gave the following figures, the contrast 

 between the ponds and streams, which were presumably 

 exposed to pollution, on the one hand, and the wells, 

 springs, and taps, on the other, being marked. 



Source of Water, 



Average Number of 

 Colonies per c.c. 



Wells, springs 

 Reservoirs ; . . 

 Ponds . . . . 

 Taps . . . . 

 Streams . . . 



According to the English ^Committee appointed to 

 consider the Standardization of Methods for the Bacterio- 

 scopic Examination of Water (1904), the ratio of the 20- 

 degree count to the 37-degree count in good waters is 



